Women walk by posters showing candidates for the presidential election in Seoul, South Korea, Tuesday, May 9, 2017. South Koreans voted Tuesday for a new president, with victory widely predicted for a liberal candidate who has pledged to improve ties with North Korea, re-examine a contentious U.S. missile defense shield and push sweeping economic changes. (Photo by Lee Jin-man/AP Photo)

A girl runs through a public water fountain to cool herself in Seoul, South Korea, Friday, June 16, 2017. A heat wave warning was issued in Seoul as temperatures soared above 32 degrees Celsius (90 degrees Fahrenheit). (Photo by Ahn Young-joon/AP Photo)

Participants march during a lantern parade marking the start of a month-long “Lotus Lantern Festival” to celebrate the upcoming Buddha's birthday, in Seoul on April 29, 2017. Buddha's birthday falls on May 3. (Photo by Ed Jones/AFP Photo)

A resident shovels the snow on the downtown road in the eastern port city of Sokcho, South Korea, 27 December 2016. (Photo by EPA/Yonhap)

Women shop at a market in Seoul, South Korea, July 26, 2016. (Photo by Kim Hong-Ji/Reuters)

A woman prays for success of her child in the college entrance examinations at a Buddhist temple a day before the test in Seoul, South Korea, November 16, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Women sort red peppers at the Tae Sung freedom village near the Military Demarcation Line (MDL), inside the demilitarised zone separating the two Koreas, in Paju, South Korea, November 22, 2016. (Photo by Kim Hong-Ji/Reuters)

Children look at a soldier as they stand in a line to take a school bus at the Daesungdong Elementary School, a school inside the demilitarised zone separating the two Koreas, in Paju, South Korea, November 22, 2016. (Photo by Kim Hong-Ji/Reuters)

Employees of the Korea Exchange (KRX) pose in front of the final stock price index during a photo opportunity for the media at the ceremonial closing event of the 2016 stock market in Seoul, South Korea, December 29, 2016. (Photo by Kim Hong-Ji/Reuters)

A woman plays on a beach as the symbol of the 2018 PyeongChang Winter Olympic Games is seen in Gangneung, South Korea February 9, 2017. (Photo by Kim Hong-Ji/Reuters)

A man works on dried pollack, near the venue for the opening and closing ceremony of the PyeongChang 2018 Winter Olympic Games in Pyeongchang, South Korea, February 10, 2017. (Photo by Kim Hong-Ji/Reuters)

Dried pollack are seen near the venue for the opening and closing ceremony of the PyeongChang 2018 Winter Olympic Games in Pyeongchang, South Korea, February 10, 2017. (Photo by Kim Hong-Ji/Reuters)

The mascot for the 2018 PyeongChang Winter Olympics Bandabi rests during the Pyeongchang Winter Festival, near the venue for the opening and closing ceremony of the PyeongChang 2018 Winter Olympic Games in Pyeongchang, South Korea, February 10, 2017. (Photo by Kim Hong-Ji/Reuters)

Elderly residents exercise on the island of Yeonpyeong, which lies in the Yellow Sea, South Korea, April 9, 2014. (Photo by Damir Sagolj/Reuters)

People walk past a building of Samsung Electronics in Seoul, South Korea February 28, 2017. (Photo by Kim Hong-Ji/Reuters)

Children wearing a lantern headband rest before a Lotus Lantern parade in celebration of the upcoming birthday of Buddha in Seoul, South Korea on April 29, 2017. (Photo by Kim Hong-Ji/Reuters)

Kim Shi-nyeo, left, mother of Han Hye-gyeong, 39, right, assists her daughter to sit down on a wheelchair as they approach to a subway stop on the way to Samsung Electronic's Seocho Headquarters on March 6, 2017 in Seoul, South Korea. Han worked at Samsung's Giheung LCD factory from 1995 and 2001, and was diagnosed as brain tumor in 2005. She had undergone a surgery and a series of chemotherapy, but became both mentally and physically disabled and could not walk on her own. (Photo by Jean Chung/Getty Images)

South Korean women protest against gender inequality and sexual harrassment in the workplace by participating in a march on March 8, 2017 in Seoul, South Korea. March 8, 2017 marks International Women's Day with events, protests and activites taking place around the world. (Photo by Jean Chung/Getty Images)

A promoter holds a sign at Myeongdong shopping district in Seoul, South Korea, May 30, 2017. (Photo by Kim Hong-Ji/Reuters)

South Korean tourist information helpers (red) guide tourists in the popular Myeongdong shopping district in Seoul on April 25, 2017. South Korea's tourist industry has been hammered by China's boycott over the deployment of US missile defence system, with visitor numbers from the Asian giant plummeting 40 percent in March, statistics showed. (Photo by Jung Yeon-Je/AFP Photo)

Buddhists hold lanterns after a parade during the Lotus Lantern Festival celebrating the upcoming birthday of Buddha on May 3, at the Jogye Temple in Seoul, South Korea, Saturday, April 29, 2017. (Photo by Lee Jin-man/AP Photo)

Workers clear snow from the grounds of Gyeongbokgung palace in central Seoul on January 13, 2017. (Photo by Ed Jones/AFP Photo)

People wearing traditional Korean hanbok dress pose for photos as they visit Gyeongbokgung palace in central Seoul on November 4, 2016. (Photo by Ed Jones/AFP Photo)

A worker sprays water onto the statue of King Sejong for a spring cleaning at the Gwanghwamun Plaza in Seoul, South Korea, Monday, April 10, 2017. King Sejong, the fourth king of the Joseon Dynasty (1392-1910), created the Korean alphabet, Hangul, in 1446. (Photo by Ahn Young-joon/AP Photo)

A South Korean honour guard performs prior to the arrival of US Defense Secretary James Mattis at the Defense Ministry in Seoul on February 3, 2017. Mattis was in the South Korean capital before going on to Tokyo, on the first overseas tour by a senior Trump administration official as concerns rise about the direction of US policy in the region under the protectionist and fiery leader. (Photo by Ed Jones/AFP Photo)

Park Yeon-Hee stands before an altar facing the North, to which prayers are offered for relatives and ancestors separated by the Korean war, near the Demilitarized Zone (DMZ) separating North and South Korea in Imjingak on January 28, 2017. On the frozen banks of the Imjin river, South Koreans divided from their families decades ago by war gathered to pay respects to their ancestors. According to tradition, Korean ceremonies for the lunar new year must be carried out by the eldest son – they lined up before an altar piled with offerings of rice cakes, fruit and fish. (Photo by Ed Jones/AFP Photo)

South Korean students attend a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. The ceremony marks the age of 19, at which a person is legally able to make life choices from voting, to drinking alcohol. (Photo by Ed Jones/AFP Photo)

A twenty-year-old South Korean wearing traditional costumes participates in the 45th Coming of Age Day ceremony at Namsangol Hanok Village in Seoul, South Korea, 15 May 2017. The Coming of Age Day is the day to celebrate and encourage the youth who have reached the age of 20, which is considered the beginning of adulthood. (Photo by Jeon Heon-Kyun/EPA)

South Korean students attend a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. (Photo by Ed Jones/AFP Photo)

South Korean students attend a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. (Photo by Ed Jones/AFP Photo)

Twenty-year-old South Koreans wearing traditional costumes participate in the 45th Coming of Age Day ceremony at Namsangol Hanok Village in Seoul, South Korea, 15 May 2017. (Photo by Jeon Heon-Kyun/EPA)

A twenty-year-old South Korean wearing traditional costumes participates in the 45th Coming of Age Day ceremony at Namsangol Hanok Village in Seoul, South Korea, 15 May 2017. (Photo by Jeon Heon-Kyun/EPA)

Twenty-year-old South Koreans wearing traditional costumes participate in the 45th Coming of Age Day ceremony at Namsangol Hanok Village in Seoul, South Korea, 15 May 2017. (Photo by Jeon Heon-Kyun/EPA)

South Korean students pose for a selfie following a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. (Photo by Ed Jones/AFP Photo)

A group of students pose for a photo wearing 1970's style school uniforms as part of an educational initiative available to visitors to the Naksan “art village” in Seoul on April 28, 2017. (Photo by Ed Jones/AFP Photo)